Four-piece fish scale expansion bolts are a type of anchor bolt designed for use in concrete and masonry applications. These bolts are characterized by their unique expansion mechanism, which provides a secure and robust connection. The "fish scale" design refers to the expansion wings that resemble the scales of a fish, which unfold within the drilled hole to create a tight grip.

These screws are usually made of stainless steel, carbon steel, or other metallic materials. Surface treatments may include zinc plating, nickel plating, passivation, etc. to improve corrosion and wear resistance. The chemical composition of the stainless steel material should be within the range specified in the steel group, the chemical composition of A2 and A4 stainless steel is specified in the following table .

Advantage:

Fish Scale Expansion: The four-piece design allows the bolt to expand within the hole, creating a strong mechanical anchorage.

Hexagonal Head: Provides a large bearing surface for better torque transfer during installation.

Corrosion Resistance: Often treated with protective coatings like zinc plating to enhance resistance to rust and corrosion.

Versatile Applications: Suitable for a variety of materials, including concrete, brick, and block walls.

Scope of Application

Construction: Used in construction projects for securing materials like formwork, safety barriers, and drywall tracks to concrete or masonry structures.

Renovation and Repair: Effective for renovation and repair work where existing structures need to be reinforced or secured with a strong and reliable fastening solution.

Machinery and Equipment Assembly: Used in the assembly of machinery and equipment where a strong and durable fastening solution is required.